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Fix linking of internal aliases 

llvm-svn: 50950
This commit is contained in:
Anton Korobeynikov 2008-05-10 14:41:43 +00:00
parent 7385b08d34
commit acbdaa2406
1 changed files with 56 additions and 29 deletions
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85
llvm/lib/Linker/LinkModules.cpp
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@ -627,20 +627,52 @@ static bool LinkAlias(Module *Dest, const Module *Src,
GlobalAlias *NewGA = NULL;
// Globals were already linked, thus we can just query ValueMap for variant
// of SAliasee in Dest
// of SAliasee in Dest.
std::map<const Value*,Value*>::const_iterator VMI = ValueMap.find(SAliasee);
assert(VMI != ValueMap.end() && "Aliasee not linked");
GlobalValue* DAliasee = cast<GlobalValue>(VMI->second);
GlobalValue* DGV = NULL;
// Try to find something 'similar' to SGA in destination module.
if (GlobalAlias *DGA = Dest->getNamedAlias(SGA->getName())) {
// If types don't agree due to opaque types, try to resolve them.
if (RecursiveResolveTypes(SGA->getType(), DGA->getType(),
&Dest->getTypeSymbolTable(), ""))
return Error(Err, "Alias Collision on '" + SGA->getName()+
"': aliases have different types");
if (!DGV && !SGA->hasInternalLinkage()) {
DGV = Dest->getNamedAlias(SGA->getName());
// Now types are known to be the same, check whether aliasees equal. As
// If types don't agree due to opaque types, try to resolve them.
if (DGV && DGV->getType() != SGA->getType())
if (RecursiveResolveTypes(SGA->getType(), DGV->getType(),
&Dest->getTypeSymbolTable(), ""))
return Error(Err, "Alias Collision on '" + SGA->getName()+
"': aliases have different types");
}
if (!DGV && !SGA->hasInternalLinkage()) {
DGV = Dest->getGlobalVariable(SGA->getName());
// If types don't agree due to opaque types, try to resolve them.
if (DGV && DGV->getType() != SGA->getType())
if (RecursiveResolveTypes(SGA->getType(), DGV->getType(),
&Dest->getTypeSymbolTable(), ""))
return Error(Err, "Alias Collision on '" + SGA->getName()+
"': aliases have different types");
}
if (!DGV && !SGA->hasInternalLinkage()) {
DGV = Dest->getFunction(SGA->getName());
// If types don't agree due to opaque types, try to resolve them.
if (DGV && DGV->getType() != SGA->getType())
if (RecursiveResolveTypes(SGA->getType(), DGV->getType(),
&Dest->getTypeSymbolTable(), ""))
return Error(Err, "Alias Collision on '" + SGA->getName()+
"': aliases have different types");
}
// No linking to be performed on internal stuff.
if (DGV && DGV->hasInternalLinkage())
DGV = NULL;
if (GlobalAlias *DGA = dyn_cast_or_null<GlobalAlias>(DGV)) {
// Types are known to be the same, check whether aliasees equal. As
// globals are already linked we just need query ValueMap to find the
// mapping.
if (DAliasee == DGA->getAliasedGlobal()) {
@ -653,47 +685,41 @@ static bool LinkAlias(Module *Dest, const Module *Src,
} else
return Error(Err, "Alias Collision on '" + SGA->getName()+
"': aliases have different aliasees");
} else if (GlobalVariable *DGV = Dest->getGlobalVariable(SGA->getName())) {
RecursiveResolveTypes(SGA->getType(), DGV->getType(),
&Dest->getTypeSymbolTable(), "");
} else if (GlobalVariable *DGVar = dyn_cast_or_null<GlobalVariable>(DGV)) {
// The only allowed way is to link alias with external declaration.
if (DGV->isDeclaration()) {
if (DGVar->isDeclaration()) {
// But only if aliasee is global too...
if (!isa<GlobalVariable>(DAliasee))
return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
"': aliasee is not global variable");
return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
"': aliasee is not global variable");
NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
SGA->getName(), DAliasee, Dest);
CopyGVAttributes(NewGA, SGA);
// Any uses of DGV need to change to NewGA, with cast, if needed.
if (SGA->getType() != DGV->getType())
DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA,
DGV->getType()));
if (SGA->getType() != DGVar->getType())
DGVar->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA,
DGVar->getType()));
else
DGV->replaceAllUsesWith(NewGA);
DGVar->replaceAllUsesWith(NewGA);
// DGV will conflict with NewGA because they both had the same
// DGVar will conflict with NewGA because they both had the same
// name. We must erase this now so ForceRenaming doesn't assert
// because DGV might not have internal linkage.
DGV->eraseFromParent();
DGVar->eraseFromParent();
// Proceed to 'common' steps
} else
return Error(Err, "Global-Alias Collision on '" + SGA->getName() +
"': symbol multiple defined");
} else if (Function *DF = Dest->getFunction(SGA->getName())) {
RecursiveResolveTypes(SGA->getType(), DF->getType(),
&Dest->getTypeSymbolTable(), "");
} else if (Function *DF = dyn_cast_or_null<Function>(DGV)) {
// The only allowed way is to link alias with external declaration.
if (DF->isDeclaration()) {
// But only if aliasee is function too...
if (!isa<Function>(DAliasee))
return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
"': aliasee is not function");
return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
"': aliasee is not function");
NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
SGA->getName(), DAliasee, Dest);
@ -716,7 +742,8 @@ static bool LinkAlias(Module *Dest, const Module *Src,
return Error(Err, "Function-Alias Collision on '" + SGA->getName() +
"': symbol multiple defined");
} else {
// Nothing similar found, just copy alias into destination module.
// No linking to be performed, simply create an identical version of the
// alias over in the dest module...
NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(),
SGA->getName(), DAliasee, Dest);
@ -728,7 +755,7 @@ static bool LinkAlias(Module *Dest, const Module *Src,
assert(NewGA && "No alias was created in destination module!");
// If the symbol table renamed the alias, but it is an externally visible
// symbol, DGV must be an global value with internal linkage. Rename it.
// symbol, DGA must be an global value with internal linkage. Rename it.
if (NewGA->getName() != SGA->getName() &&
!NewGA->hasInternalLinkage())
ForceRenaming(NewGA, SGA->getName());